A substrate processing apparatus includes a stage for supporting a substrate in an evacuable processing chamber. The stage may have a function of controlling a temperature of a substrate. An example of the stage is disclosed in Patent Document 1.
Patent Document 1 discloses therein a temperature control device including a mounting table, a chiller unit, a heating unit, a flow path switching unit, and a controller. The mounting table has a first coolant passageway extending along a circumferential direction of the mounting table at a central region of the mounting table and a second, coolant passageway extending along the circumferential direction of the mounting table at a peripheral region of the mounting table. The chiller unit has an output port and a return port. The output port is connected to an inlet of the first coolant passageway through a first flow line. The return port of the chiller unit is connected to an outlet of the second coolant passageway through a second flow line.
A heating unit for heating a coolant flowing through the first flow line is connected to the first flow line. The flow path switching unit is connected to the second flow lines. The flow path switching unit has a plurality of valves for switching connection relation between the first coolant passageway and the second coolant passageway. In this device, a temperature of the coolant supplied to the first and the second coolant passageway is individually adjusted by controlling opening/closing of the valves of the flow path switching unit and the operation of the heating unit.
Patent Document 1: Japanese Patent Application Publication Mo. 2006-286733
In the device disclosed in Patent Document 1, when a temperature of a substrate is deviated from a target temperature by an external factor such as heat input from a plasma, temperature variation of the substrate can be corrected by individually controlling a temperature of the coolant supplied to the first and the second coolant passageway. However, in this device, the heating unit for heating the temperature is installed at the outside of the mounting table and, thus, there is a difference between operation timing of the heating unit and timing of supplying the coolant of a controlled temperature to the mounting table. Accordingly, in the device disclosed in Patent Document 1, a long period of time may be required until the temperature variation caused by the external factor is corrected.